In one of the bloodiest days in recent months, insurgents killed at least 25 people, mostly Iraqi police, in multiple attacks across the volatile Sunni Triangle (search) on Tuesday and a militant group claimed it executed eight Iraqi employees of an American security company, saying they had collaborated with U.S. occupational forces.

With the insurgency that is targeting mainly U.S. troops, Iraqi officials and security forces escalating ahead of Jan. 30 parliamentary elections, Iraqi lawmakers appealed for national unity, fearing the militants could trigger civil war.

"The terrorists intend to destroy Iraq's national unity," said a statement issued by the Interim National Assembly (search). "Their intentions are to harm this country which faces crucial challenges amid a very difficult period."

"The response to these acts needs national awareness and strong unity between all Iraqis," said the temporary legislature, which is to be replaced by an elected assembly after the first free elections in Iraq since 1958. The new parliament's main task will be to write the country's new constitution.

Brig. Gen. Jeffery Hammond, assistant brigade commander in the 1st Cavalry Division (search) that controls Baghdad, said attacks by insurgents are expected to escalate further in the run-up to the ballot.

"We anticipate that the enemy will [continue with] attacks, intimidation, assassinations and other messages designed to destroy life in Baghdad," Hammond said, adding that Iraqi security forces will bear the brunt of providing security for the elections and that U.S. troops will back them up only if needed.

Shiite Muslims, who make up around 60 percent of Iraq's people, have been strong supporters of the elections, which they expect to reverse the longtime domination of Iraq's Sunni minority. The insurgency is believed to draw most of its support from Sunnis, who provided much of Saddam Hussein's former Baath Party membership.

The local Al-Iraqiya television network reported that a total of 34 people died on Tuesday, including 26 policemen and national guards, but that figure could not be independently confirmed.

In an apparent attempt to improve the efficiency of security forces, an Iraqi Defense Ministry spokesman said Tuesday that the paramilitary Iraqi National Guards will be merged with the armed forces.

The ING, which is also part of the Defense Ministry, has born the brunt of insurgent attacks in the past months.

Near Saddam's hometown of Tikrit, gunmen attacked a police station, overwhelmed 12 Iraqi policemen there, slit their throats and then blew up the building, said Lt. Col. Saad Hmoud, a local police official.

The deputy governor of the restive Anbar province, Moayyad Hardan al-Issawi, was assassinated near Ramadi, east of Baghdad, police official Abdel Qader al-Kubeisy said. Gunmen who shot him left a statement next to his body: "This is the fate of everyone who deals with the American troops." The statement was signed by radical Mujahedeen al-Anbar group, or the "Fighters of Anbar."

Such flagrant attacks appear designed to cause panic and desertion among Iraqi officials and security forces — considered by militants to be American collaborators — and provoke a sectarian conflict between Shiites and Sunnis.

Militants released a videotape Tuesday, saying they have executed eight and released two Iraqis who were employed by Sandi Group, an American security company, and had been held hostage since Dec. 13.

The insurgents claiming to represent three Iraqi militant groups — the Mujahedeen Army, the Black Banner Brigade and the Mutassim Bellah Brigade — said in the tape obtained by APTN that "the eight have been executed because it was proven that they were supporting the occupational army." The other two will be released for the lack of evidence, a statement read by one of the militants.

In other strikes Tuesday, a car bomb killed five Iraqi National Guardsmen and injured 26 near Baqouba, a town 57 kilometers (35 miles) northeast of Baghdad, after the paramilitary troops had cordoned off an area in order to disarm a roadside bomb, said U.S. Maj. Neal O'Brien.

In Baqouba itself, unidentified gunmen assassinated Capt. Na'em Muhanad Abdullah, a local police commander, and wounded three other men, a spokesman said.

Elsewhere Tuesday, a car bomb exploded in the village of Muradiya, 30 kilometers (18 miles) northeast of Baghdad, killing five civilians and wounding dozens, said Ahmed Fouad, a doctor in the Baqouba General Hospital.

In Mosul, 360 kilometers (225 miles) northwest of Baghdad, a gunman attacked a police station in the northeastern Hadbaa district, said police Capt. Ahmed Khalil. One policeman died in the attack.

In the central city of Samarra an attacker detonated his car in the city center wounding 10 people, including three children, police Maj. Saadoun Ahmed Matroud.

Shortly after the explosion, people were told through mosques loud speakers to stay indoor because of a curfew, and U.S. and Iraq troops set up roadblocks, witnesses said.

In Babil province south of Baghdad, police said they arrested 10 armed men in a raid in the area of Jbila after intelligence indicated the suspects were allegedly plotting to attack a police station there, Capt. Hady Hatif said.

At Samarra, U.S. troops killed three rebels when they attacked an American post with small-arms and rocket propelled grenades, the U.S. military said. There were no injuries to U.S. soldiers or damage to equipment.